Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton
We analyzed Sr and Nd isotopic compositions of granitic and metamorphic rocks from the Namaqualand area, South Africa. The Concordia Granite, a member of the Spektakel Suite, near Garies, has a Rb-Sr whole rock isochron age of 1017±30Ma with an initial Sr isotopic ratio of 0.7110±0.0029. This age co...
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Department of Earth System Science, Faculty of Science, Fukuoka University/Graduate School of Science and Technology, Niigata University/Department of Geoscience and Technology, Graduate School of Engineering, Tohoku University
2001
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ftnipr:oai:nipr.repo.nii.ac.jp:00002417 2023-05-15T17:10:59+02:00 Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton Yuhara,Masaki Kagami, Hiroo Tsuchiya, Noriyoshi 2001-07 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2417 http://id.nii.ac.jp/1291/00002417/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2417&item_no=1&attribute_id=18&file_no=1 en eng Department of Earth System Science, Faculty of Science, Fukuoka University/Graduate School of Science and Technology, Niigata University/Department of Geoscience and Technology, Graduate School of Engineering, Tohoku University https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2417 http://id.nii.ac.jp/1291/00002417/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 55, 127-144(2001-07) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2417&item_no=1&attribute_id=18&file_no=1 South Africa Namaqualand Concordia Granite Nababeep Granite Gneiss Sr and Nd isotopic compositions Rb-Sr and Sm-Nd whole rock isochron ages Departmental Bulletin Paper P(論文) 2001 ftnipr 2022-11-12T19:43:14Z We analyzed Sr and Nd isotopic compositions of granitic and metamorphic rocks from the Namaqualand area, South Africa. The Concordia Granite, a member of the Spektakel Suite, near Garies, has a Rb-Sr whole rock isochron age of 1017±30Ma with an initial Sr isotopic ratio of 0.7110±0.0029. This age coincides with the SHRIMP U-Pb zircon age reported from the Okiep Copper District (OCD) within an error. Sm-Nd model ages of this granite (TCHUR : 1030-1195Ma, TDM : 1579-1710Ma) are younger than those in the OCD. The Nababeep Granite Gneiss can be divided into two groups, High and Low NdI Groups, in the Sm-Nd system. The former gives a Rb-Sr whole rock isochron age of 1131±62Ma, and the latter indicates a Rb-Sr isochron age of 1246±62Ma. The gneisses of the High NdI Group are distributed in the southern part of the study area. On the other hand, the Low NdI Group are mainly distributed in the northern area. The boundary between the two parts accords closely with the boundary between lower and upper granulite-facies, which suggests that the Nd isotopic compositions of source rocks of these gneisses were not uniform, and that there is a gap between northern and southern areas. This affects the Nd isotopic composition of the latter granitic rocks such as the Concordia Granite. Report Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan |
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Open Polar |
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National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
South Africa Namaqualand Concordia Granite Nababeep Granite Gneiss Sr and Nd isotopic compositions Rb-Sr and Sm-Nd whole rock isochron ages |
spellingShingle |
South Africa Namaqualand Concordia Granite Nababeep Granite Gneiss Sr and Nd isotopic compositions Rb-Sr and Sm-Nd whole rock isochron ages Yuhara,Masaki Kagami, Hiroo Tsuchiya, Noriyoshi Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
topic_facet |
South Africa Namaqualand Concordia Granite Nababeep Granite Gneiss Sr and Nd isotopic compositions Rb-Sr and Sm-Nd whole rock isochron ages |
description |
We analyzed Sr and Nd isotopic compositions of granitic and metamorphic rocks from the Namaqualand area, South Africa. The Concordia Granite, a member of the Spektakel Suite, near Garies, has a Rb-Sr whole rock isochron age of 1017±30Ma with an initial Sr isotopic ratio of 0.7110±0.0029. This age coincides with the SHRIMP U-Pb zircon age reported from the Okiep Copper District (OCD) within an error. Sm-Nd model ages of this granite (TCHUR : 1030-1195Ma, TDM : 1579-1710Ma) are younger than those in the OCD. The Nababeep Granite Gneiss can be divided into two groups, High and Low NdI Groups, in the Sm-Nd system. The former gives a Rb-Sr whole rock isochron age of 1131±62Ma, and the latter indicates a Rb-Sr isochron age of 1246±62Ma. The gneisses of the High NdI Group are distributed in the southern part of the study area. On the other hand, the Low NdI Group are mainly distributed in the northern area. The boundary between the two parts accords closely with the boundary between lower and upper granulite-facies, which suggests that the Nd isotopic compositions of source rocks of these gneisses were not uniform, and that there is a gap between northern and southern areas. This affects the Nd isotopic composition of the latter granitic rocks such as the Concordia Granite. |
format |
Report |
author |
Yuhara,Masaki Kagami, Hiroo Tsuchiya, Noriyoshi |
author_facet |
Yuhara,Masaki Kagami, Hiroo Tsuchiya, Noriyoshi |
author_sort |
Yuhara,Masaki |
title |
Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
title_short |
Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
title_full |
Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
title_fullStr |
Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
title_full_unstemmed |
Rb-Sr and Sm-Nd systematics of granitic and metamorphic rocks in the Namaqualand Metamorphic Complex, South Africa:Implications for evolution of marginal part of Kaapvaal craton |
title_sort |
rb-sr and sm-nd systematics of granitic and metamorphic rocks in the namaqualand metamorphic complex, south africa:implications for evolution of marginal part of kaapvaal craton |
publisher |
Department of Earth System Science, Faculty of Science, Fukuoka University/Graduate School of Science and Technology, Niigata University/Department of Geoscience and Technology, Graduate School of Engineering, Tohoku University |
publishDate |
2001 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2417 http://id.nii.ac.jp/1291/00002417/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2417&item_no=1&attribute_id=18&file_no=1 |
genre |
Memoirs of National Institute of Polar Research Polar Research |
genre_facet |
Memoirs of National Institute of Polar Research Polar Research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2417 http://id.nii.ac.jp/1291/00002417/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 55, 127-144(2001-07) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2417&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766067811946332160 |